A prime consideration in any catalytic process is maximization of the catalyst lifetime. That is to say, it is desirable to have the catalyst perform at or near its optimum efficiency for as long as possible. The process of interest in this application is the catalytic hydrogenation of carbohydrates in aqueous solution.
The discovery leading to the invention described herein is that spent catalyst used in the hydrogenation of a feedstock of glucose in aqueous solution contains gluconic acid, an oxidation product of glucose. Based on this discovery, use of feedstocks low in dissolved oxygen subsequently were shown to lead to substantially increased lifetime of hydrogenation catalysts, thereby affording a considerable improvement over existing processes.